Apart from confirming that Facebook’s deal to buy VR company Oculus was even more expensive than first publicized, a full day’s worth of questioning in the Dallas courtroom yielded few surprises.

A $1bn was paid out in order to keep key staff on the Oculus team and to provide incentives in addition to the $2bn (£1.6bn) fee announced back in 2014.

Zenimax is the company that alleges its software was stolen in order to make Oculus a success and the 32-year-old appeared to have little patience for the claims made by the company as he has also used his time in Dallas to visit community groups.

“It’s pretty common when you announce a big deal that people just come out of the woodwork and claim they own some part of the deal,” he told the court after being called as a witness.

“The idea that Oculus products are based on someone else’s technology is just wrong.”

Facebook is being sued for $2 billion by Zenimax, owner of id Software. John Carmack, co-founder of id, had joined Oculus as its full-time chief technology officer from Zenimax and the company alleges that Carmack took intellectual property belonging to Zenimax when he left the firm.

Responsible for pioneering the “first person shooter” genre with titles such as Doom and Quake, Carmack is a legend in the games industry.

Evidence supporting its claims was destroyed, Zenimax also alleged.

Oculus team is responsible for bringing virtual reality to the masses and creating innovative hardware – its Rift headset, Facebook says.

Were it not for its help in the early stages in developing the software that made the headset capable of doing anything, the Oculus team wouldn’t have been able to do any of that, Zenimax says.

The significance of Zenimax’s role in the early days of Oculus were disputed by Zukerberg in his testimony which took up most of the day’s session.

“Like most people in the court, I’ve never even heard of Zenimax before,” he said.

However, some believe that this may play into the hands of the prosecution.

When Facebook purchased the company, it did not carry out due deligience, lawyers for Zenimax accuse Facebook of. The huge deal apparently happened very quickly over a single weekend.

His views on the future of virtual reality were rather discussed during much of Zuckerberg’s appearance on the stand – his first time testifying in a court room.

He had filmed the first steps of his daughter, Max, in VR as it was the best way to capture such a moment, he told the court room.

Zukerberg however said that the technology wasn’t “fully there yet”. How he sees virtual reality as an integral part of the network’s 10-year strategy has been outlined by Zuckerberg at recent events.

The trial is expected to last around three weeks and is into its fifth day.

Palmer Luckey, the co-founder of Oculus, is expected to be called to the stand later this week.